The present invention relates to a method for manufacturing a twisted yarn with a spindle rotor having a hollow spindle axle to which is connected a substantially radially outwardly extending yarn guide channel through which a yarn is passed which after exiting from the yarn guide channel forms a yarn balloon and is guided to a centering element that is positioned on an extension of the axis of the hollow spindle axle whereby into the space defined by the yarn balloon dissolved fiber material is introduced that is guided in the axial direction through the spindle rotor. The present invention also relates to a device for performing the inventive method having at least one spindle rotor that is rotatably supported on a spindle frame, which spindle rotor has a hollow spindle axle and connected thereto a yarn guide channel extending substantially radially outwardly, wherein a yarn exiting from the yarn guide channel forms a yarn balloon and is guided from the yarn balloon to a centering element positioned on an extension of the axis of the hollow spindle axle and is guided from there to a yarn winding device. The device further has a feeding device for introducing dissolved fiber material into the space defined by the yarn balloon which feeding device has an inlet line that is coaxially inserted into the spindle rotor.
Such a method and device are disclosed in German Patent 37 21 364. In the known method a flowable medium is introduced without disturbances into the space defined by the yarn balloon wherein the spindle rotor is provided with a plurality of guide vanes that are arranged in a spoke-like manner and wherein the yarn guide channel extends through one of these guide vanes. The flowable medium to be introduced into the space defined by the yarn balloon, in the case of a two-for-one twisting spindle, is conditioned air or a two-phase medium, for example, in the form of droplets suspended in air which are to impart a special effect on the yarn. It is also suggested that with this method fiber material can be introduced into the space defined by the yarn balloon.
It is an object of the present invention to provide a method for manufacturing a twisted yarn comprised of at least two yarn components of the aforementioned kind wherein the two-for-one spindle is supplied with dissolved fiber material and wherein the finished twisted yarn is removed from the two-for-one spindle.
In German Offenlegungsschrift 1 785 366 (1972) a spinning method is described which at the time of the disclosure was referred to as "element spinning". Pursuant to this method, fiber material is arranged to form a fiber band which is then formed to a rotating balloon wherein per revolution of the balloon at least two twists are imparted to the fiber band and the resulting yarn is removed from the spindle. The device for performing this known spinning method comprises a spinning chamber positioned on a spindle in which the fiber material is introduced through a fiber inlet tube that extends coaxially to the spindle axle and through a channel which extends radially to the spindle rotor. Within the spinning chamber a collector ring for the fiber material is provided which fiber material is formed to a roving. The fiber band exiting from the stretching device is guided through a channel which is positioned within the spindle axle wherein a first twist is imparted to the fiber band and exits from this channel in the radial direction to form a balloon rotating about the spinning chamber where a second twist is imparted to the fiber band.
The same principle has been used in German Offenlegungsschrfit 40 23 397 (1992) which discloses a method for spinning fibers to yarns as well as a spinning device for performing the method. According to this method, the fiber material is introduced to a spinning rotor and the yarn is removed in the counter-rotational direction so as to form a rotating arc about the spinning rotor. The device for performing this known spinning method comprises a spinning rotor supported on a two-for-one rotor which is rotatably supported in a stationary housing. The fiber exiting the spinning rotor is removed via a removal channel, positioned within the two-for-one twister and extending in an arc exterior to the spinning rotor, in order to be guided to the common axis of the spinning rotor and the two-for-one rotor is then guided upwardly through the drive device of the double wire rotor. This imparts a second twist to the yarn. The fiber material is introduced into the spinning rotor through an inlet channel within the two-for-one rotor whereby the inlet opening of the channel is symmetrical to the axis of the two-for-one rotor and the exit opening of the channel is eccentrically positioned to this axis.
The East German publication 88 001 shows a method for manufacturing a textile yarn which is comprised of at least two spun fibers. In this method two rotor spinning devices positioned atop one another are used whereby the fiber removal tube of the upper rotor spinning device is introduced into the rotor of the lower rotor spinning device and is arranged coaxially to the fiber removal tube of the lower rotor spinning device. The fiber produced within the upper rotor spinning device is combined with the fiber produced in the lower rotor spinning device and wound about it. A yarn balloon is not employed in this method.